Conventionally, a cord (e.g. power cord) of an electronic appliance is detachable from the body of the appliance for easy handling and exchange. With this type of connector, a detached connector causes power interruption, or an almost detached connector can cause electric leakage due to imperfect contact between connectors.
To solve such a problem, a structure including a mechanism for locking connectors has been disclosed conventionally (refer to patent literature 1, for instance).
FIGS. 8A, 8B, and 8C are external perspective views of a locking mechanism of a conventional connector described in patent literature 1. As shown in FIG. 8A, the locking mechanism includes panel 11 of apparatus body 10, opening 12 provided in panel 11, and shielding plate 13 provided on panel 11. Shielding plate 13, attached to panel 11 rotatably centering on a supporting point (not shown), opens and shields opening 12. Shielding plate 13 is provided with notch 13a at the bottom-end edge thereof. Further, the connector locking mechanism includes connector 14. Connector 14 is attached to the inner part of opening 12 and electrically connected to a circuit (not shown) inside apparatus body 10.
As shown in FIG. 8B, with shielding plate 13, the arc center of a fan-shaped member having a pair of arc outer circumferences is pivotally supported to a fixed shaft (not shown), being vertically rotatable. Hence, vertically rotating shielding plate 13 makes connector 14 open to the outside and be shielded from the outside.
Power cord 21 has plug 22 on the front end thereof for electrically connecting to connector 14. Stage 23 on the back of plug 22 is formed smaller than plug 22.
In the locking mechanism of a conventional connector thus structured, shielding plate 13 attached to panel 11 of the apparatus body is first rotated upward to make connector 14 be in an open state. Next, plug 22 of power cord 21 is inserted through opening 12 to make connector 14 fit with plug 22 to be electrically connected.
After that, as shown in FIG. 8C, shielding plate 13 is rotated downward to make opening 12 of panel 11 shieldable. On this occasion, notch 13a provided at the bottom-end edge of shielding plate 13 fits with stage 23 on the back of plug 22. This structure allows plug 22 to be held in a space between shielding plate 13 and connector 14 to engage plug 22.
However, the following problem is found in the conventional connector locking mechanism described in above patent literature 1.
For instance, the locking mechanism can be released if the apparatus body is placed upside down or inclined, or if the cord is moved. An attempt to adequately work the locking mechanism causes shielding plate 13 to be vertically rotated with difficulty, resulting in attaching and detaching of the cord with difficulty. Further, shielding plate 13 needs to be made of a hard material, which causes damage and breakage due to a load added to stage 23 on the back of plug 22.    [Patent literature 1] Japanese Utility Model Unexamined Publication No. H07-14575